The present invention generally relates to a digital scanner for scanning images. More specifically, the present invention is directed to a method and apparatus for accurately scanning documents and for processing digital data to provide digital images stored in memory, which can be retrieved for printing on support material or for displaying on a display screen.
In a conventional digital scanner, a light source is used to illuminate a document having the image to be scanned. The conventional digital scanner also includes a platen glass upon which the document rests and a platen cover. The light emmitted by the light source illuminates the document and is reflected off and imaged by an optical system or lens system towards either a CCD sensor array or full width array, which converts the reflected light into electrical signals which are eventually converted into digital image data. An image processing circuit electronically registers the image, and converts the electrical signals into digital image data so that the digital image data can be utilized by an image output terminal, network citizen, or memory device.
In the prior art, a printer or other digital imaging system is typically coupled to a digital scanner for scanning an original image (e.g. document) and employs an initial step of charging a photoconductive member (photoreceptor) to a substantially uniform potential. The charged surface of the photoconductive member is thereafter exposed to a light image of an original document to selectively dissipate the charge thereon in selected areas irradiated by the light image. This procedure records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document being reproduced. The latent image is then developed by bringing a developer including toner particles adhering triboelectrically to carrier granules into contact with the latent image. The toner particles are attracted away from the carrier granules to the latent image, forming a toner image on the photoconductive member, which is subsequently transferred to a copy sheet. The copy sheet having the toner image thereon is then advanced to a fusing station for permanently affixing the toner image to the copy sheet.
The approach utilized for multicolor electrostatographic printing is substantially identical to the process described above. However, rather than forming a single latent image on the photoconductive surface in order to reproduce an original document, as in the case of black and white printing, multiple latent images corresponding to color separations are sequentially recorded on the photoconductive surface. Each single color electrostatic latent image is developed with toner of a color complimentary thereto and the process is repeated for differently colored images with the respective toner of complimentary color. Thereafter, each single color toner image can be transferred to the copy sheet in superimposed registration with the prior toner image, creating a multi-layered toner image on the copy sheet. Finally, this multi-layered toner image is permanently affixed to the copy sheet in substantially conventional manner to form a finished copy.
A digital scanner for processing images to provide digital data and transmitting the digital data to a workstation, comprising: means for scanning images; means for processing the images to provide digital data; means for storing the digital data in a memory; and means for transmitting the digital data in the memory to the workstation, while concurrently scanning, processing and storing other images as digital data. The processing means includes compressing the digital data before storage in the memory.
A digital scanner for processing images to provide digital data and transmitting the digital data to a workstation, comprising: a memory; a scanning unit scanning images; an image processing unit processing the images to provide digital data; a direct memory access controller storing the digital data in the memory; and means for transmitting the digital data in the memory to the workstation, while concurrently scanning, processing and storing other images as digital data. The digital scanner as further comprises a data compression unit compressing digital data before storage in the memory.
A digital scanner for processing images to provide digital data and transmitting the digital data to a workstation, comprising: a memory; a data compression unit; a scanning unit scanning images and converting the images into digital data; an image processing unit receiving digital data from the scanning unit and processing the digital data for storage in the memory or for further processing by the data compression unit; a direct memory access controller receiving processed digital data from the image processing unit or from the data compression unit, and storing the processed digital data in memory; and a scanner interface retrieving digital data from memory and transmitting the digital data to the workstation. The workstation is coupled to at least one of an image output terminal, network or storage medium. The image output terminal is a printer or a display for outputting the scanned and processed images.
The workstation accesses the network or the internet for uploading scanned and processed images transmitted to the workstation by the digital scanner. The workstation accesses the internet or network for downloading images, transmits the downloaded images to the digital scanner for processing, receives the processed images from the digital scanner and outputs the processed images to at least one of an image output terminal, network or internet. The digital scanner transmits the digital data in the memory to the workstation, while concurrently scanning, processing and storing other images as digital data.
The data compression unit may be one of an ITU G3/G4 and JPEG. The digital scanner further comprises a second data compression unit, wherein the data compression unit is an ITU G3/G4 and the second data compression unit is a JPEG.
The digital scanner further comprises a FIFO coupled to the image processing unit, direct memory access controller, the ITU G3/G4 and the JPEG, wherein the FIFO temporarily stores digital data received from the image processing unit and outputs the stored digital data to the direct memory access controller, JPEG or ITU G3/G4.
The direct memory access controller stores digital data received from the FIFO, JPEG or ITU G3/G4 in the memory.
The digital scanner further comprises a computing unit coupled to the scanner interface, the memory, and direct memory access controller. The computing unit is also coupled to the scanning unit and image processing unit.
The scanner interface of the digital scanner may be a SCSI interface.
The scanning unit of the digital scanner includes an image sensing unit comprising a full width array.
A method for scanning and processing an image, comprising: scanning images; processing the images to provide digital data; storing the digital data in a memory; transmitting the digital data in the memory to the workstation, while concurrently scanning, processing and storing other images as digital data. The method further comprises the step of compressing the digital data before storing the digital data in memory.
A method for scanning and processing an image comprising: transmitting a scan image signal from a workstation to a digital scanner; initializing digital scanner; scanning images to provide digital data; processing the digital data; storing the digital data in direct memory access blocks in memory; transferring the digital data in direct memory access blocks from memory to a workstation by way of a scanner interface, while other images are scanned, digital data is processed and stored in memory. The method further comprises the step of compressing the digital data before storing the digital data in memory.
A digital imaging system comprising: means for scanning images; means for processing the images to provide digital data; means for storing the digital data in a memory; a print engine controller; an image-processor controller; means for transmitting the digital data in the memory to the print engine controller, while concurrently scanning, processing and storing other images as digital data; a photoreceptor; a plurality of charging units charging the photoreceptor; a plurality of exposure units receiving the digital data from the print engine controller by way of the image-processing controller, and exposing the photoreceptor to place a latent image on the photoreceptor based on the image signals; a plurality of developer structures, each developer structure being connected to a corresponding dispenser, and each dispenser having a different toner; a transfer unit transferring the toner on the photoreceptor to a support material; a fusing unit fusing the toner to the support material; and a cleaner cleaning the photoreceptor after the support material has passed through the transfer unit. The digital imaging system further comprises a workstation, wherein the digital data is transmitted from memory to the print engine controller by way of the workstation. The processing means of the digital imaging system includes compressing the digital data before storage in the memory.